PHP rand function giving empty values - still not working

Question

I have this little tid-bit of my code, which is eventually sent to a MySQL database. The rest of the code is sound, but this code likes to give me empty data some of the time. Is there any way to prevent this from happening?

Edit: Here's the whole chunk

//random Species
$sp_one = mt_rand(1,10);    
$one_species = "Water Leaper";

//random Genetics

if($one_species == "Water Leaper")
{
    $one_gene = mt_rand(1,5);

    if($one_gene < 3)
    {
        $one_genetics = "1";
    }

    else if($one_gene < 5)
    {
        $one_genetics = "2";
    }

    else
    {
        $one_genetics = "3";
    }
}

//random Gender
$one_sex_num = mt_rand(1,2);

if($one_sex_num == 1)
{
    $one_gender = "Female";
}

if($one_sex_num == 2)
{
    $one_gender = "Male";
}

//Entering it
$sql="INSERT INTO creatures (species, sex, location, genetics)
VALUES('{$one_species}','{$one_gender}', 's1','{$one_genetics}')";

mysqli_query($con,$sql);

Please specify what you mean by give me empty data some of the time, especially, what are the values of $one_gene and $one_genetics after the code gave you empty data. — Oswald
– Oswald, Commented Aug 3, 2013 at 14:32
In a MySQL table column. It pops up randomly and causes errors on my site that I have to go and fix manually. — AmazingGrace
– AmazingGrace, Commented Aug 3, 2013 at 14:32
That problem is unrelated to this code. Check the code that inserts the data into the database for errors, and post here if necessary. — George Cummins
– George Cummins, Commented Aug 3, 2013 at 14:32
why are doing a rand between 1 a 5 if you only want a number between 1 and 3? — Matías Cánepa
– Matías Cánepa, Commented Aug 3, 2013 at 14:34

Mundi · Accepted Answer · 2013-08-03 14:40:42Z

1

First, your if clauses seem a bit redundant. More concise code:

if ($one_gene <3)      { $one_genetics = "1"; }
elseif ($one_gene <5)  { $one_genetics = "2"; }
else                   { $one_genetics = "3"; }

This should always return a value - if everything else fails, "3".

Maybe better even:

$one_genetics = ($one_gene + 1) / 2; // integer division

edited Aug 3, 2013 at 14:40

answered Aug 3, 2013 at 14:34

Mundi

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1 Comment

Mundi Over a year ago

Great - you have discovered that the error is elsewhere! Please accept the answer and post a new question with the relevant code.

botenvouwer · Accepted Answer · 2013-08-03 15:14:35Z

I don't know what you are doing exacly but maby you can take a look at this:

<?php

    $animals = array();

    $animals[] = array('dog', 78, array('Komondor','Old English Sheepdog'));    
    $animals[] = array('Drosophila', 8, array('Vestigal','Ebony')); 

    $number_animals = count($animals) - 1;
    $list_size = 30;

    for($q = 1; $q <= $list_size; $q++){

        $rand = rand(0, $number_animals);
        $animal = $animals[$rand];

        $number_species = count($animal[2]) - 1;

        $rand = rand(0, $number_species);
        $randsex = rand(0, 1);

        $species = $animal[2][$rand];
        $sex = ($randsex ? 'male' : 'female');
        $genes = $animal[1];

        echo "$q: $species - $sex - $genes <br>";
    }

?>

See a live demo at: here

It pics random animals with specs if you want you can modify to your own wishes.

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